Safety latch mechanism



March 1, 1960 w. F. STACKHOUSE 2,926,945

SAFETY LATCH MECHANISM Filed July 12, 1957 4 Iweazom 39 WeZZsFS'Wme, 387 19 Q9 W,\TM7 3 1 SAFETY LATCH MECHANISM Wells F. Stackhouse, Andover,Mass., assignor to American Locker Company, Inc., Boston, Mass., :1corporation of Delaware Application July 12,1957, Serial No. 671,579 2Claims. (CL 292--333) This invention relates to safety latch mechanismand more particularly to coin controlled checking lockers. A coincontrolled and key operated lock is commonly employed 'with each lockercabinet, the lock being secured to the cabinet in position to cooperatewith the closure door. When the cabinet is not in use the lock is inunlocked position and the door can be opened for depositing parcels inthe cabinet. The depositing of a coin in the lock functions to permitthe key to be rotated to the door locking position and thereafter to beremoved and taken by the patron as his check.

The locking unit employs a rotary door locking bolt having a latchassociated therewith and adapted normally to prevent movement of thebolt from the unlocked position to the door locking position. Alsoassociated with the latch is abutment means disposed in door engagingposition and automatically operative to. move the latch to inoperativeposition when the door is closed, thereby preventing the patron fromthrowing the bolt to locked position before he has closed the door, allas shown in Patent 2,437,742.

Heretofore, and as shown in said patent, the latch is positively movedto inoperative position when the door is closed and such positiveoperation of the latch has resulted in considerable difficulties anddamage, hereinafter described. The present invention provides meanspermitting inward movement of the abutment member without moving thelatch out of the path of movement of the locking bolt when abnormalresistance to such movement is placed on the latch, thereby eliminatingthese objections. The production of novel mechanism for performing thisfunction comprises the primary object of the invention.

These and other features of the invention will be best understood andappreciated from the following description of a preferred embodimentthereof selected for purposes of illustration and shown in theaccompanying drawing in which:

Fig. l is a front elevation of a checking cabinet employing a lockingunit embodying my invention,

Fig. 2 is an enlarged side elevation of the locking unit partly insection,

Fig. 3 is a fragmentary like view with the parts in another position,

Fig. 4 is an enlarged view of a portion of Fig. 3,

Fig. 5 is a fragmentary rear view of the locking unit, and

Fig. 6 is a fragmentary section taken on line 6-6 of Fig. 4.

In Fig. l of the drawing, 10 indicates a bank of coin controlledchecking cabinets, and 12 the closure door of one of the cabinets. Thelock mechanism 14 is secured to a marginal portion of the cabinet inposition to cooperate with and lock the door. This lock mechanismcomprises a body member 15 having a front plate 16 secured thereto bybolts 18. The front plate is disposed over and fills an opening throughthe cabinet wall, the lower end of the plate being provided with a lip19 engaging behind United States Patent 0 ice the cabinet wall and theupper end being equipped with a lock normally covered by a pivotedclosure plate 20 and having a lock bolt 21 for engaging behind thecabinet wall.

The unit also carries a lock 22 having a bolt 24 for engaging andlocking the cabinet door 12 in the closed position of Fig. 1. A counter26 operated by this lock is adapted to register one unit at eachactuating cycle of the lock. The lock barrels at 20 and 22 are keyoperated and each contains key operated plungers and tumblers. The bolt24 is connected to rotate with the barrel of the lock 22 and isrotatable to and between two extreme locked and unlocked positions, asindicated in Fig. 5, and is held in either of such positions by meansincluding a spring 25. a I

Occasionally a patron inadvertently turns thelock 22 to the cabinetlocking position before fully closing the l door 12, and in such casethe patron loses his coin into the cash box and the lock is locked inthe cabinet door open position so that the patron to check properly mustagain turn the key anti-clockwise to unlock the lock and then insertanother coin in the lock and repeat the operation, being sure all thewhile that the door is in a closed position. To eliminate this troublethe lock is provided with a latch pin 28 slidably mounted in the body 15in position to engage within a hole 30 in the lock bolt 24 when the lockis in unlocked position. A U-shaped housing member 32 has its longer legfixed to the rear end of the latch pin and one leg of a U-shaped leafspring 34 is fixed to said longer leg within the U-shaped member.

An abutment member has a straight plunger portion 36 slidably mounted inthe body 15 beneath the latch 28 and a compression spring 38 on theplunger rearwardly of a collar 39 fixed to the plunger normally forcesthe plunger forwardly to the position of Fig. 4 wherein its forward endportion is in the path of movement of a plate 40 fixed to and forming apart of the door 12. An arm 42 carried by and extending upwardly fromthe rear end of the plunger 36 has its free end disposed within themember 32 between its shorter forward leg and the forward leg of theleaf spring 34. The expansion of the spring 38 normally forces theplunger 36 forwardly into the path of door closing movement of the doorand simultaneously therewith the arm 42 moves the latch 28 forwardlyinto the hole 30 of the lock bolt 24 when the lock is in unlockedposition. Thus the lock bolt cannot be moved to door locking positionuntil the door is closed.

When the door is moved to closed position the abutment member 36-42,together with the member 32, spring 34 and latch pin 28, are allnormally moved rearwardly as a unit. However, if abnormal resistance tosuch movement is placed on the latch pin, as by exerting turningpressure on the key 25 and bolt 24, such rearward movement of the member36-42 will merely compress the leaf spring, as illustrated in brokenlines in Fig. 4, and will not move the latch pin 28 from the hole 30.

Heretofore, as shown in said Patent 2,437,742, the latch pin 28 has beenpositively connected to the abutment member 36 and various troubles anddamage to the latch pins has resulted when the door is closed whileplacing pressure on the latch pin through turning pressure on the key.Such turning pressure may be exerted innocently by a patron ordeliberately for any of several reasons. In any event, such action willfrequently result in stripping and damaging the latch end of the pin 28as the door is slammed closed and the pin suddenly withdrawn from thehole 30 under pressure causing substantial resistance to such movement.

Attempts have been made by unscrupulous persons to beat the lock bymanipulating pressure on the key while simultaneously slamming the door.One object of such actions to eati sedthermechanism to turn so rapidly,when the latch is suddenly released .thattthevpawls vin .theilock do nothave time to function in their proper notches, thereby circumventingnormal functioning of the lock.

=Atternpts have "also been made through such manipulationo'f the key to'cause abnormal turning of the counter -26, thereby-running up anunwarranted number on the counter. The previous positive functioning ofthe members 28 'and 30 have thus caused damage and other troubles whichare remedied by-the present invention 111m coin controlled mechanism, alock having 'a'bolt for locking a door in closed position, meansmounting the bolt-for movement todoor-lo'cking and released positions,

an abutment member movably mounted'in the'lock, ta

' Iatchin-the' lock, meansmormallyioperative tomove the -latch forwardlyinto theipath'of door locking movement of the-boltandsimultaneouslytherewith the abutment member forwardly into the pathof door closing mm.

.ment of the door, asshousingtearried by, the latch, the

second named means including an arm carried'by the abutment member andhaving a terminal portion engaging the housing forwardly of saidportion, and a compression spring disposed in the housing between saidportion and the rear Wall .of the housing, said spring normallymaintaining said portion in said engagement with the housing butpermitting independent rearward movement of said portion when abnormalresistance to rearward movement is placed on the latch.

2. The mechanism defined in claim 1 in which said spring is a U-shapedleaf spring having its rear leg fixed to the rear wall of the housingand its forward-leg engaging said terminal portion of the arm.

References Cited in the file of this patent UNITED STATES PATENTSJakeway Apia-8, 1952

